In Mesopotamian myth, Anšar and Kisar were a pair of primordials, respectively male and female, and perhaps representing the heaven (An) and earth (Ki). According to the Babylonian Epic of Creation they were the second
pair (after Lahmu and Lahamu) of offspring of Apsu (abzu) and Tiâmat. (An alternative interpretation of the passage makes them the children of Lahmu and Lahamu.) Ansar and Kisar in turn bore Anu (An), the supreme god of heaven.

From Gods, Demons and Symbols of Ancient Mesopotamia : An Illustrated Dictionary written by Jeremy Black and Anthony Green